fix(ui): restore output views without normal commands (#452)

* fix(renderer): suppress mode changes during output scroll

* Avoid normal commands during output scroll restore

* Clarify output viewport restore redraw

* Simplify output scroll test command stub

Author: jensenojs

lua/opencode/ui/output_window.lua

@@ -201,6 +201,19 @@ function M.get_visible_top_line(win)
   return (ok and line and line > 0) and line or nil
 end
 
+---@param win integer
+---@param topline integer
+function M.restore_view_topline(win, topline)
+  vim.api.nvim_win_call(win, function()
+    local view = vim.fn.winsaveview()
+    view.topline = math.max(1, topline)
+    view.skipcol = 0
+    vim.fn.winrestview(view)
+    -- Apply the restored viewport before later line('w$') reads inspect it.
+    vim.cmd('redraw')
+  end)
+end
+
 ---@param win? integer
 function M.reset_scroll_tracking(win)
   if win then
@@ -764,9 +777,7 @@ function M.setup_autocmds(windows, group)
         if rendered and rendered.line_start then
           local restored_top = math.max(1, rendered.line_start + anchor_offset)
           pcall(vim.api.nvim_win_set_cursor, windows.output_win, { restored_top, 0 })
-          pcall(vim.api.nvim_win_call, windows.output_win, function()
-            vim.cmd('normal! zt')
-          end)
+          pcall(M.restore_view_topline, windows.output_win, restored_top)
           return
         end
       end

lua/opencode/ui/renderer/scroll.lua

@@ -3,31 +3,6 @@ local output_window = require('opencode.ui.output_window')
 
 local M = {}
 
-local function with_window_event_autocmds_ignored(fn)
-  local previous = vim.o.eventignore
-  local ignored = {
-    WinEnter = true,
-    WinLeave = true,
-    BufEnter = true,
-  }
-
-  for event in previous:gmatch('[^,]+') do
-    if event ~= '' then
-      ignored[event] = true
-    end
-  end
-
-  local events = vim.tbl_keys(ignored)
-  table.sort(events)
-  vim.o.eventignore = table.concat(events, ',')
-
-  local ok, err = pcall(fn)
-  vim.o.eventignore = previous
-  if not ok then
-    error(err)
-  end
-end
-
 ---@param win integer
 ---@return boolean
 local function window_wraps(win)
@@ -44,6 +19,12 @@ local function get_text_width(win)
   return math.max(1, width - textoff)
 end
 
+---@param win integer
+---@param line integer
+local function restore_view_with_line_at_bottom(win, line)
+  output_window.restore_view_topline(win, line - vim.api.nvim_win_get_height(win) + 1)
+end
+
 ---@param buf integer
 ---@param win integer
 ---@param target_line integer
@@ -129,18 +110,7 @@ function M.scroll_win_to_bottom(win, buf)
   end
 
   if needs_bottom_align then
-    local windows = state.windows
-    if windows and vim.api.nvim_get_current_win() == windows.input_win then
-      with_window_event_autocmds_ignored(function()
-        vim.api.nvim_win_call(win, function()
-          vim.cmd('normal! zb')
-        end)
-      end)
-    else
-      vim.api.nvim_win_call(win, function()
-        vim.cmd('normal! zb')
-      end)
-    end
+    restore_view_with_line_at_bottom(win, target_line)
   end
 
   output_window._prev_line_count_by_win[win] = line_count

tests/replay/lazy_render_scroll_spec.lua

@@ -113,6 +113,17 @@ describe('replay lazy-render upward loading', function()
     assert.are.equal(1, output_window.get_visible_top_line(win))
     assert.are.equal(5, vim.api.nvim_win_get_cursor(win)[1])
 
+    local modechanged_count = 0
+    local group = vim.api.nvim_create_augroup('OpencodeLazyRenderViewRegression', { clear = true })
+    vim.api.nvim_create_autocmd('ModeChanged', {
+      group = group,
+      pattern = 'i:n',
+      callback = function()
+        modechanged_count = modechanged_count + 1
+      end,
+    })
+    local cmd_stub = require('luassert.stub')(vim, 'cmd')
+
     vim.api.nvim_exec_autocmds('WinScrolled', {
       buffer = state.windows.output_buf,
       modeline = false,
@@ -123,5 +134,10 @@ describe('replay lazy-render upward loading', function()
     end)
 
     assert.is_true(loaded, 'Expected viewport-at-top WinScrolled to load older replayed messages')
+    assert.equals(0, modechanged_count)
+    assert.stub(cmd_stub).was_not_called_with('normal! zt')
+
+    cmd_stub:revert()
+    pcall(vim.api.nvim_del_augroup_by_id, group)
   end)
 end)

tests/unit/cursor_tracking_spec.lua

@@ -474,7 +474,7 @@ describe('renderer.scroll_to_bottom', function()
     cmd_stub:revert()
   end)
 
-  it('uses zb when the followed bottom line is below the viewport', function()
+  it('bottom-aligns when the followed bottom line is below the viewport', function()
     local lines = {}
     for i = 1, 40 do
       lines[i] = 'line ' .. i
@@ -483,26 +483,19 @@ describe('renderer.scroll_to_bottom', function()
     vim.api.nvim_win_set_height(win, 5)
     vim.api.nvim_win_set_cursor(win, { 1, 0 })
 
-    local cmd_stub = stub(vim, 'cmd').invokes(function(cmd)
-      if cmd == 'normal! zb' then
-        vim.api.nvim_win_call(win, function()
-          vim.fn.winrestview({ topline = 36 })
-        end)
-        return
-      end
-      return vim.api.nvim_cmd(vim.api.nvim_parse_cmd(cmd, {}), {})
-    end)
+    local cmd_stub = stub(vim, 'cmd')
 
     local scroll = require('opencode.ui.renderer.scroll')
     scroll.scroll_win_to_bottom(win, buf)
 
     local cursor = vim.api.nvim_win_get_cursor(win)
     assert.equals(40, cursor[1])
-    assert.stub(cmd_stub).was_called_with('normal! zb')
+    assert.equals(40, output_window.get_visible_bottom_line(win))
+    assert.stub(cmd_stub).was_not_called_with('normal! zb')
     cmd_stub:revert()
   end)
 
-  it('uses zb when a wrapped bottom line grows past the last screen row', function()
+  it('keeps the visual end selected when a wrapped bottom line grows past the last screen row', function()
     local long_line = string.rep('x', 80)
     local longer_line = string.rep('x', 180)
 
@@ -511,12 +504,7 @@ describe('renderer.scroll_to_bottom', function()
     vim.api.nvim_set_option_value('wrap', true, { win = win, scope = 'local' })
     vim.api.nvim_buf_set_lines(buf, 0, -1, false, { long_line })
 
-    local cmd_stub = stub(vim, 'cmd').invokes(function(cmd)
-      if cmd == 'normal! zb' then
-        return
-      end
-      return vim.api.nvim_cmd(vim.api.nvim_parse_cmd(cmd, {}), {})
-    end)
+    local cmd_stub = stub(vim, 'cmd')
 
     local scroll = require('opencode.ui.renderer.scroll')
     scroll.scroll_win_to_bottom(win, buf)
@@ -528,7 +516,7 @@ describe('renderer.scroll_to_bottom', function()
     local cursor = vim.api.nvim_win_get_cursor(win)
     assert.equals(1, cursor[1])
     assert.equals(#longer_line - 1, cursor[2])
-    assert.stub(cmd_stub).was_called_with('normal! zb')
+    assert.stub(cmd_stub).was_not_called_with('normal! zb')
     cmd_stub:revert()
   end)
 
@@ -545,26 +533,58 @@ describe('renderer.scroll_to_bottom', function()
     state.ui.set_windows({ output_win = win, output_buf = buf, input_win = input_win, input_buf = input_buf })
     vim.api.nvim_set_current_win(input_win)
 
-    local winleave_count = 0
+    local events = {
+      BufEnter = 0,
+      ModeChanged = 0,
+      WinEnter = 0,
+      WinLeave = 0,
+    }
     local group = vim.api.nvim_create_augroup('OpencodeScrollImeRegression', { clear = true })
+    vim.api.nvim_create_autocmd('WinEnter', {
+      group = group,
+      callback = function()
+        events.WinEnter = events.WinEnter + 1
+      end,
+    })
     vim.api.nvim_create_autocmd('WinLeave', {
       group = group,
-      buffer = input_buf,
       callback = function()
-        winleave_count = winleave_count + 1
+        events.WinLeave = events.WinLeave + 1
+      end,
+    })
+    vim.api.nvim_create_autocmd('BufEnter', {
+      group = group,
+      callback = function()
+        events.BufEnter = events.BufEnter + 1
+      end,
+    })
+    vim.api.nvim_create_autocmd('ModeChanged', {
+      group = group,
+      pattern = 'i:n',
+      callback = function()
+        events.ModeChanged = events.ModeChanged + 1
       end,
     })
 
+    local cmd_stub = require('luassert.stub')(vim, 'cmd')
+
     vim.api.nvim_win_set_height(win, 5)
     vim.api.nvim_win_set_cursor(win, { 1, 0 })
     config.values.ui.output.always_scroll_to_bottom = true
 
     renderer.scroll_to_bottom()
 
     assert.equals(input_win, vim.api.nvim_get_current_win())
-    assert.equals(0, winleave_count)
+    assert.same({
+      BufEnter = 0,
+      ModeChanged = 0,
+      WinEnter = 0,
+      WinLeave = 0,
+    }, events)
     assert.equals(50, vim.api.nvim_win_get_cursor(win)[1])
+    assert.stub(cmd_stub).was_not_called_with('normal! zb')
 
+    cmd_stub:revert()
     config.values.ui.output.always_scroll_to_bottom = false
     pcall(vim.api.nvim_del_augroup_by_id, group)
   end)